HDU 1251 统计难题

字典树又一基本题

代码：

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
using namespace std;
#define N 1027

struct node
{
    int count;
    node *next[30];
}*root;

char ss[13];

node *create()
{
    node *p;
    p = (node *)malloc(sizeof(node));
    p->count = 1;
    for(int i=0;i<26;i++)
        p->next[i] = NULL;
    return p;
}

void release(node *p)
{
    for(int i=0;i<26;i++)
    {
        if(p->next[i] != NULL)
            release(p->next[i]);
    }
    free(p);
}

void insert(char *ss)
{
    int i=0,k;
    node *p = root;
    while(ss[i])
    {
        k = ss[i++] - 'a';
        if(p->next[k] == NULL)
            p->next[k] = create();
        else
            p->next[k]->count++;
        p = p->next[k];
    }
}

int search(char *ss)
{
    int i=0,k,j;
    node *p = root;
    int now = 0;
    while(ss[i])
    {
        k = ss[i++] - 'a';
        p = p->next[k];
        if(p == NULL)
            return 0;
        else
            now = p->count;
    }
    return now;
}

int main()
{
    int i=0,j,k;
    root = create();
    while(gets(ss)&&ss[0]!='')
    {
        insert(ss);
    }
    i=0;
    while(scanf("%s",ss)!=EOF)
    {
        printf("%d
",search(ss));
    }
    release(root);
    return 0;
}